SALT LAKE CITY — A mother's heart is often overwhelmed with feelings for her newborn child, but many would never expect that heart to give out just before or months after giving birth.
However, peripartum cardiomyopathy affects one in every 3,000 to 4,000 previously healthy women who are welcoming babies into the world. Ten percent of those then require ongoing medication, a heart transplant or a mechanical heart-assist device to survive.
Without any warning or known cause, the potentially devastating condition typically develops within the final month of pregnancy or within the first five months after. It ends up weakening the woman's heart so that it no longer pumps blood efficiently.
"The heart becomes overloaded, it is trying to pump blood out of the heart, into the rest of the body and it is having a tough time getting enough out there," Benjamin Horne, director of cardiovascular and genetic epidemiology at Intermountain Medical Center, said of PPCM. Horne is one of 20 researchers, including physicians form Intermountain's Maternal Fetal Medicine program, the University of Utah and the VA Hospital, that recently discovered a common gene mutation in women with PPCM.
"This gives us and other researchers a roadmap that tells us where to look in the human genome for more information about the disease," he said, adding that the new knowledge may lead to the development of early testing that could help to "reduce or even prevent some of the complications of this disease."
Intermountain's study is the first of its kind to include not just one large sample of DNA, but three separate trials, including nearly 100 cases. Blood samples collected from women who had suffered from PPCM, as well as older women who had never experienced cardiac problems were sent to a highly specialized lab in Iceland where they can isolate genetic mutations.
Horne said researchers had no idea what to expect, but two-thirds of the women with PPCM shared a genetic mutation on chromosome 12, which is responsible for blood pressure regulation and muscle contraction in the uterus and the heart.
The mutation apparently exists in one out of every six individuals, Horne said. And while the mortality rate associated with PPCM is quite low, 3 percent or lower, women of child-bearing age, he said, are typically too young to be dying from heart failure.
"Heart failure typically occurs in people in their 60s, 70s and 80s. They've lived a long life and hopefully we can help them live longer, but when you get something like that in your 20s and 30s, it drastically alters your future," Horne said.
About six years ago, doctors and nurses began collecting samples from women with PPCM, also creating an online support network, "A Mother's Heart," to disperse information about the disease. The study that ended up locating the mutated gene began four years ago and was funded by grants from the Deseret Foundation and the R. Harold Burton Foundation.
"It is something we want to prevent," Horne said. "None of these women should have to deal with that, if we can at all help them to avoid it, that's one of the motivations behind this."